“Don’t fall asleep” -- words to live by for Elm Street teens. Not a problem for fans wide awake with fear (and glee) as they experience these first 8 Nightmare movies released from 1984 to 2003. Each features Robert Englund’s masterfully macabre incarnation of slouch-hatted, razor-fingered Freddy Krueger, who mixes wicked wit with even wickeder mayhem as he haunts teens when they’re asleep and most vulnerable. A newspaper article about children who died after having fearsome nightmares provided the real-life springboard for filmmaker Wes Craven’s breakthrough series. Perhaps that underlying reality helps make these shockers so unnerving. Or maybe it’s just that we all like a good scare…and that this series consistently, imaginatively delivers some of the best.